1. Field of the Invention
This invention relates to a process for preparing the cyclic phosphate ester of substituted 9-(1,3-dihydroxy-2-propoxymethyl)purines which are useful as antiviral agents.
2. Related Disclosure
The compound 9-(1,3-dihydroxy-2-propoxymethyl)guanine cyclic phosphate ester is a potent antiviral agent and has been prepared by methods disclosed in European Patent Application No. 74,306. The present invention relates to an improved process for preparing the cyclic phosphate ester of 9-(1,3-dihydroxy-2-propoxymethyl)guanine and of 2,6-diamino-9-(1,3-dihydroxy-2-propoxymethyl)purine. The present process involves a two step reaction which eliminates the multiple separation and purification steps required in previous known processes. The instant process also results in increased yields of the product.